We investigate a variant of evolution-communication P systems
where the computation is performed in two substeps. First, all possible an-
tiport rules are applied in a non-deterministic, maximally parallel way, moving
evolution rules across membranes. In the second substep, evolution rules are
applied to suitable objects in a maximally parallel way, too. Thus, objects can
be the subject of change, but are never moved themselves. As result of a halt-
ing computation, we consider the multiset of objects present in a designated
output membrane. When using catalytic evolution rules, we already obtain
universal computational power with only one catalyst and one membrane. For
systems without catalysts we obtain a characterization of the Parikh images
of ET0L languages
